Field of Invention
The current invention concerns a biological tissue transplant coated with a stabilized multilayer alginate coating and a method for preparation of such stabilized multilayer coating. The method involves formation of the coating comprising three layers of the alginate with a polyamino acid barrier emplaced between a primary and a secondary layer. The secondary "halo" layer of soft gel is formed by a gel gradient created between weakly bound cross-linking gelling divalent cations of a soluble alginate used for the primary layer of the coating and non-gelling counter ions of a non-ionic alginate of the secondary layer of the coating. The tertiary layer of the coating is generated by dispersing a suspension of a biological tissue core coated with the primary and secondary layers into a gelling divalent cations solution. The method additionally involves emplacement of a thin and delicate polyamino acid polymer barrier for retention of biological tissue within the primary alginate layer of the coating during creation of the gel gradient followed by ionic exchange.
The method results in the transplant coated with the primary alginate layer surrounded by the thin polyamino acid polymer barrier, with the secondary layer of soft gel and with the tertiary layer formed by gelling the alginate with the divalent cations, thereby forming the outer layer of a non-fibrogenic coating.